Williams announced her pregnancy at 20 weeks through a Snapchat photo that she says was released accidentally. Williams says that she found out about the pregnancy shortly before the Australian Open -- which she played in ... and won.

In recent months Williams, who has always been outspoken, has spoken out even further on social issues, using her break from tennis to advance a platform of equality. With a new baby girl on the way, we might not hear from her in a while, although Williams has adamantly said that she wants to get back to tennis as soon as next year.

Serena's sister will play in the Round of 16 on Sunday after earning her 74th US Open match victory -- fourth most in the Open era -- but there's no doubt Venus will take some time over the next few days to celebrate with the new mom.